Digital Signage is an effective means of mass communication. They are cost effective, can be interactive and a single program can be spread through multiple mediums across domains. The backbone of the drive to digitize information is the Digital Signage Software. These software enable you to create programs suited to the platform that will host these Digital Signage.

Digital Signage Software comes in three broad categories:

Outdoor Signage software:  these soft wares enable one to create large displays used in outdoor billboards, large LCD displays in malls, stadiums, etc. They are usually programs that may or may not have touch screen options. Depending on the size of the display various underlying technologies are used and while buying the software, one must have a clear idea of the scale of the project and find suitable digital signage software.
Indoor Signage software: these soft wares enable one to create programs used in small kiosks, stand alone advertising displays for cafés, travel companies, etc. These are small programs which tend to loop with minimal fuss and graphic content.
Mobile signage software: the latest entrant in the digital signage world is the soft wares that allows you to create digital signage for mobile phones. As use of multimedia phones spread, it the best and easiest source to spread and gather digital information. This family of soft wares allows a creator to customize content in small programs that can be spread through pear to pear sharing in platforms, e.g. Blackberry list, iPhones, etc.

Each of the above family of digital signage software cones with its set of technology so ensure that the hardware is compatible with the underlying software. If the world of digital signage software seems to confusing just follow the general rules:

Start of with one segment of the digital signage segment and use software compatible with the latest display hard wares like plasma LCD, etc.
Research the best licensing deal from companies.
Try out the trial versions to check if they suffice your specific needs and then negotiate for a license deal
Once you have established your self in the relevant segment then expand to others. This allows you to have a body of work to showcase. In addition, allows you to keep costs down.
If investment capital is scare then start out with small project for the mom and pop stores and local malls using free wares amply available online.